I am installing a 47Rh (replacing the 727) behind my 91. I have replaced the adapter plate now the stater does not mount correctly. I know I need to replace the starter but will my Flexplate work. Will I need to upgrade wiring for the new starter.

 

Been there did that, yes the starter has one bolt hole that doesn't line up, 2nd gen one will fix that. Be aware that the starter is clocked differently than the 1st gen starter, it will come close to the frame maybe even rub it slightly when the motor torques up.

No you should not have to update your wires. You may need to untape the big wire and small wire to reach where the terminals are now on the starter. Then retape them.

Will the orginal flexpate work?

Yes, but I would not use the orginal flexplate, I'm sure you may have read that alot of guys break or crack their orginal flexplates. I currently have a SFI approved aftermarket flexplate in mine, overkill yes, but its not going to break at my power levels. I think most guys here would suggest a 2nd gen flexplate, order it from cummins (I don't have a part number right now)

Do you have the plug that plugs into the valve body connector for the LU and OD functions? It makes wiring one alot easier if you have one.

Good luck with it and let us know how it turns out.

 

another question, what would be the best way to shift in the lockup and overdrive. Also when should I shift?

 

Use switches, You need 12V supply directly to the harness, and supply a ground to both O/D and lockup. O/D 40+, lockup, anything over 35MPH. And don't forget to unlock it.
3-pin plug. If I recall, 12V is the middle, and the grounds are the outside pins.

 

Switches is what I use. OD is still controlled by the 93 PCM on mine. Just remember to unlock it. Once its in OD locked it will not come out unless you unlock the converter first.

The 3 pin connector layout is:
Front pin is for OD
Center pin gets +12v from a fused source that is on with key on.
Rear pin is for Lockup

Here's a good reference: http://www.transmissioncenter.net/alto_3.htm

With 3.55 I would lock a Stock converter up at 40 and up. OD locked at 50 and up. These speeds will depend on your rear axle ratio.
Don't lug it with the torque locked and you should be alright. Just remember the lockup is alot harder on the rest of the transmission parts because now you actually have some power going through.

I forgot something the in the last post, when your swapping in the 47RH, switch the TV cable lever from your 727. The 2nd gen trucks use a different lever position and doesn't work too well with our setups.

 

I agree with JD730 that you should upgrade the flexplate. Kellypckp your truck is 3-speed auto correct? If so you will have 3.08 gears. Really when driving your truck you will find out when it feels right(to you) to put it in overdrive. Myself I don't like to be in overdrive under 65. When getting on the highway I flip my od switch at 60, but if I stay under 65 I just keep it in 3rd. I think you will find that overdrive will be used only on the highway.

Paul

 

you all are very helpfull in this swap. Is there any other problems that I might run into. little tips that might help. Once again I am very thankful for all your input. Working on getting some pictures.

 

I am having problems finding a shaft seal for the 47rh. I have the 205 transfer case and the coupler in to larger to go into the seal. The coupler shaft is 2.126 and the bore I believe to be 2.560. Have any you had this problem.

Also has anyone tried those cheaper starters on E-Bay if so they any good?

 

Pull the output seal out of the 47RH, discard, use ultra black or your favorite rtv to seal the trans to transfer case flange. Thats what I did. Mine's been in for 20,000 miles.

Be aware that there is a drain of sorts in the transmission flange, thats why rtv is necessary, the newer transfer cases seal on the shaft and leaves a dead space there that will drain any fluid out that gets there.

I don't know about the E-bay starters. I got mine from a place pretty local to me that does all of our rebuilding. I want to say it was under $200 outright.

 

I built a new trany tower to bolt to the the exsiting cross member. I made it so the engine has a little tilt back.

My problem is that the 85 crew cab is now hitting the transfer case. I am not sure if I built the tower to tall. Or if I am going to have to install a body lift to clear the transfer.

My question is how much if any should the engine tilt back? How much angle should there be on the drivelines.